Rubber band gear assembly



. June 21, 1960 s, so 2,941,623

- RUBBER BAND GEAR ASSEMBLY Filed Feb. 10, 1959 2 FIG.

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INVENTOR. G3 SIDNEY A. TARRSON 22 M k g/ United States Patent RUBBER BAND GEAR ASSEMBLY Sidney a. Tarrson, 5060 Marine Drive, Chicago, Ill.

Filed Feb. 10, 1959, Ser. No. 792,314

1 Claim. (Cl. 1ss-s7 This invention relates to improvements in motor-driven toy vehicles or the like, and in particular relates to a drive assembly for such articles which incorporate a gear train driven by a rubber band power source.

Small mechanically-driven toys are customarily provided with a springdriven motor connected through a gear train to the portion of the toy to be rotated. Ordinarily the spring is wound manually by means of a key. Such structure, while effective in operation for most purposes, is expensive in manufacture, and presents the further disadvantage that the spring is easily broken, in which event there is no practical means for spring re placement. Thus if the spring breaks or becomes damaged, the toy becomes wholly inoperative and is useless.

According to the present invention, a mechanicallydriven toy is provided with drive means in which a rubber band replaces the conventional spring as the power source. The elastic band is coupled to a step-down gear train which provides a smooth, even, and controlled rotational speed.

An object of the present invention is the provision of a mechanical drive assembly of the character described in which means are provided to permit a broken rubber band to be quickly and easily replaced by a fresh rubber band, such means enabling the fresh rubber band to be readily mounted in the toy vehicle and. coupled to the gear train of the drive assembly.

Another object of the invention is the provision of a mechanical drive assembly of the character described in which the rubber band is connected to and carries a drive gear, the latter being slidably mounted on the body of the vehicle and being movable out of meshing engagement with the remainder of the gear train for manual winding-up of the rubber band.

Still another object of the present invention is the provision of a mechanically driven toy, the parts of which, including the gear assembly, are capable of being molded entirely from plastic, and in which the sole motor power is provided by a conventional rubber band, whereby manufacture of the toy is extremely economical.

Additional objects and advantages of the present invention will become apparentduring the course of the following specification when taken in connection with the accompanying drawings, in which:

Fig. 1 is a side elevational view of a toy incorporating the drive assembly of the present invention;

Fig. 2 is an enlarged vertical section through the rear portion of the toy which incorporates the drive assembly, as taken along line 22 of Fig. 4;

Fig. 3 is a section taken along line 3-3 of Fig. 2;

Fig. 4 is a bottom plan View of the rear portion of the toy showing the drive assembly incorporated therein; and

Fig. 5 is a plan view of the drive gear of the assembly.

Referring in detail to the drawings, there is illustrated in Fig. l, by way of example, a toy automobile adapted to roll upon wheels 18. The toy automobile has a hollow body 12 of selected shape and design which in- 2,941,623 Patented June 21, 1960 cludes a top wall 12a and depending side walls 12b and 12c. The pair of front wheels 18 areafilxed to the ends of a front axle 14, and the pair of rear wheels 18 are similarly aflixed to the ends of a rear axle 16. The axles 14 and 16 extend through respective openings in the sidewalls 12b and 12c and are journalled therein: The wheels 18 are preferablyof the conventional rubber type, although they may be made of plastic or other suitable material.

At the center of the rear axle 16 a pinion gear 20 is rigidly afiixed. A drive gear 22 of considerably larger diameter than the pinion gear 20 is mounted within the automobile body in position to register with said pinion gear.

The drive gear 22 has enlarged hub portions 24 and'26 which project laterally from the opposite faces of said gear, as shown in Figs. 3 and 4. Integral with these hub portions are respective terminal hub extensions 28 and 30 of smaller diameter. The drive gear 22 and its hub portioris and hub extensions may be moulded of plastic as an integral unit, as may the automobile body and other parts of the assembly.

A pair of mounting brackets 32 and 34 for the drive gear 22 are carried by the top wall 12a of theautomobile body, the brackets 32 and 34 depending from said top wall and being arranged parallel to each other and closely spaced from each other. The brackets 32 and 34- have elongated longitudinal slots 36 sized to receive the hub extensions 28 and 30. The drive gear 22 1's thus mounted rotatably between the brackets 32 and 314 with the hub extensions 28 and 30 rotatably received within tl're' slots 36 and the enlarged hub portions 24 and 26 slidably engaging the inner faces of said brackets,-as shown in Figs. 3 and 4. The slots 36 have closed bottom ends 36a of arcuate shape which normally act as bearings forth'e hub extensions 28 and 30.

The power for driving the aforementioned gear assembly is provided'by a continuous looprubbe'r' band 40 of conventional type. The rubber band 40 is removably and replaceably coupled to the drive-gear 22 infa manner which will now be described.

The drive gear 22 has an elongated rectangular slot 42 at its center, this slot extending through both hub portions 24 and 26 and hub extensions 28 and 30. The drive gear 22 also has a narrow radial slot 44 which extends from the circumferential edge of said drive gear, at a point between a pair of drive gear teeth, to the central slot 42. It will be observed in Fig. 5 that the central slot 42 has a length which is considerably greater than the width of the radial slot 44, so that the central slot 42 has end portions 42a and 4212 which extend laterally at either side of the area of communication between the radial slot 44 and central slot 42.

The rubber band 40 is mounted at its ends upon a pair of hook members or posts 46 and 48 which are rigidly secured to or formed integrally with the automobile body side walls 12b and 120. The central portion of the rubber band 40 extends through the rectangular central slot 42 of the drive gear 22. When the rubber band 40 is wound up by twisting it about its longitudinal axis, in the manner indicated in Figs. 3 and 4, it is torsionally tensioned, and upon release will impart a torsional force upon the drive gear 22, causing the drive gear to rot-ate as the rubber band unwinds. Normally, the rubber band would unwind instantaneously and the drive gear 22 would be rotated extremely rapidly. However, the meshing engagement of the drive gear 22 with. the pinion gear 20 greatly retards the rotational speed of the drive gear 22 so that the rubber band 40 unwinds relatively slowly and evenly. The rear axle 16 and its wheels 18 are therefore driven at a controlled rate and in a smooth and even manner until the rubber band 40 has unwound.

To wind the drive assembly, the drive gear 28 may be slid upwardly toward the top of the bracket slots 36 until its teeth are out of meshing engagement with the teeth of, the pinion gear. 20; The resilience of the unwound rubber band 40 permits this upward sliding movement of the. drive gear 22; The drive gear may then be manually rotateduntil the, rubber band 40 is twisted to'the maximum permissible limit, and the drive gear is then permitted to slide down to the lower end of the, slots 36 until it is, again in meshing engagement with the pinion gear 20. The driveassembly is now'in condition for operation, and the toy automobile is set down one fiat surface, the rear wheels 18 being driven through the step-down gear train by the twisted and torsionally-tensioned rubber band to propel the toy vehicle. It will be appreciated that, while the drive gear 22 is capable of being manually lifted in the bracket slots 36 for purposes of Winding up the rubber band 40, the resilience of the wound rubber band 40, and its tendency to stretch in a straight line between the mounting hooks or posts 46, 48, maintains the drive gear hub extensions 28,30 at the bottom ends of the slots 36 with the drive gear 22 engaged with the pinion gear 20. The wound rubber band 40 thus serves to urge the drive gear and pinion gear in mesh with each other. It will be apparent that additional gears may be added to the gear train if a greater step-down gear ratio is desired. 7

As an alternate manner of winding up the rubber band 40, thetvehiole 10 may be pressed down upon a flat surface and pushed rearwardly, the rear wheels 18 turning in a reverse direction and rotating the pinion gear 20, the latter in turn rotating the drive gear 22 and thereby twisting the rubber band 40. Again, the resilience of the rubber band 40 maintains the drive gear 22 in meshing relationship with the pinion gear 20 during this winding operation. 7.

An important feature of the invention is the means provided for replacing the rubber band 40 in the event that it becomes broken. In the course of time, rubber bands are known to become brittle so that they easily break under strain. In addition, the rubber band 40 can be easily broken it is wound too tightly. In this event it is an easy matter for the user to replace the broken rubber band with a new one.

To replace the rubber band 40, ,the, drive gear 22 is turned by hand until its radial slot 44 is in registry with the bracket slots 36, this position being shown in Fig. 2. A fresh rubber band is then inserted through the bracket slots 36 above the drive gear 22 and held slightly stretched between the side walls 12b and 120. The rubber band is then moved downwardly in the slots 36 so that its center portion enters the radial slot 44 "and moves therethrough to the central radial slot 42. The rubber band is then slightly turned about its axis until its center portionsare located in the central slot end portions 42a and- 42b, as shown in Fig. 5. Theends'of the rubberband are then i looped over the mounting hooks or posts 46, 48, and the drive assembly is ready for 'use.

While a preferred embodiment of the invention has been shown and described herein, it is obvious that numerous additions, changes and omissions may be made without departing from the spirit and scope of the inventionv What is claimed is: 5 A drive assembly for mechanical toys or the like having a driven member to be rotated, said drive assembly comprising an elastic band serving as power means for said drive assembly, means removably mounting the ends of said elastic band on a fixed portion of said toy vehicle, and a gear train connecting said elastic band. to said driven member, said gear train including a driven-gear concentrically mounted on said driven member, a drive gear, and means for removably coupling said drive gear with, said rubber band for rotation of said drive gear by torsional force of said rubber band, said coupling means comprising a radial slot in said drive gear and an elongated slot at the center of said .drive gear in communication with said radial slot.

References Cited in the file of this patent ,UNITED STATES PATENTS 1,529,832 Dengler t Mar. 17, i925 FOREIGN PATENTS 361,936 France Nov. 24, 1906 682,252 Great Britain Nov. 5, 1952 

